• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.189-193
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• 2010

SIP 프로토콜 기반 VoIP 서비스는 편리함과 저렴한 통신비용으로 사용자 수가 급증하고 있다. 하지만 Text 형태의 SIP 헤더 정보를 UDP 방식으로 전송하기 때문에 손쉽게 위변조 할 수 있으며, 최근 SIP를 통해 제공되는 다양한 형태의 부가서비스에 대한 보안 위협이 증가하고 있다. FMC 폰을 통해 제공되는 동시착신, 착신전환, 3인통화 등과 같은 부가서비스에 대한 공격을 통해 과금우회 공격 등을 수행할 수 있다. 따라서 본 연구에서는 FMC 환경에서 제공되는 주요 SIP 부가서비스를 대상으로 각각의 취약성에 대해 조사 분석하였으며, 분석된 내용을 중심으로 SIP 기반 인터넷전화 부가서비스에 대한 공격 시나리오를 단계별로 설계 및 개발하였다.

• Annual Conference of KIPS
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• 2023.05a
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• pp.496-498
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• 2023

Brain tumor segmentation problem has challenges in the tumor diversity of location, imbalance, and morphology. Attention mechanisms have recently been used widely to tackle medical segmentation problems efficiently by focusing on essential regions. In contrast, the fusion approaches enhance performance by merging mutual benefits from many models. In this study, we proposed a 3D dual fusion attention network to combine the advantages of fusion approaches and attention mechanisms by residual self-attention and local blocks. Compared to fusion approaches and related works, our proposed method has shown promising results on the BraTS 2018 dataset.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5291-5298
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• 2012

Beta-asarone is one of the main bioactive constituents in traditional Chinese medicine Acorus calamu. Previous studies have shown that it has antifungal and anthelmintic activities. However, little is known about its anticancer effects. This study aimed to determine inhibitory effects on LoVo colon cancer cell proliferation and to clarify the underlying mechanisms in vitro and in vivo. Dose-response and time-course anti-proliferation effects were examined by MTT assay. Our results demonstrated that LoVo cell viability showed dose- and time-dependence on ${\beta}$-asarone. We further assessed anti-proliferation effects as ${\beta}$-asarone-induced apoptosis by annexin V-fluorescein isothiocyanate/propidium iodide assay usinga flow cytometer and observed characteristic nuclear fragmentation and chromatin condensation of apoptosis by microscopy. Moreover, we found the apoptosis to be induced through the mitochondrial/caspase pathway by decreasing mitochondrial membrane potential (MMP) and reducing the Bcl-2-to-Bax ratio, in addition to activating the caspase-9 and caspase-3 cascades. Additionally, the apoptosis could be inhibited by a pan-caspase inhibitor, carbobenzoxy-valyl-alanyl-aspartyl-[O-methyl]-fluoromethylketone (Z-VAD-FMK). When nude mice bearing LoVo tumor xenografts were treated with ${\beta}$-asarone, tumor volumes were reduced and terminal deoxynucleotide transferase-mediated dUTP nick end labeling (TUNEL) assays of excised tissue also demonstrated apoptotic changes. Taken together, these findings for the first time provide evidence that ${\beta}$-asarone can suppress the growth of colon cancer and the induced apoptosis is possibly mediated through mitochondria/caspase pathways.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1110-1114
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• 1998

The crystallization behaviors and electrical conductivities of the glasses heat-treated at various times and temperatures in the CuO-Bi$_2$O$_3$-V$_2$O$_{5}$ glass system were investigated. Among glass samples with various compositions, the highest conductivity obtained in the 31CuO-14Bi$_2$O$_3$-55V$_2$O$_{5}$ (mol%) glass sample. The 31CuO-14Bi$_2$O$_3$-55V$_2$O$_{5}$ (mol%) glass sample crystallized by heat treatment at 358$^{\circ}C$ for 8h had 2.67$\times$10$^{-2}$ $\Omega$$^{-1}$ $cm^{-1}$ /, which was much high value as a solid electrolyte. Compared to the glass sample, the heat- treated glass sample was increased in conductivity by an order of 10$^3$-10$^4$due to the formation and growth of BiVO$_4$ and CuVO$_3$crystals.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4360-4366
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• 2010

It is impossible for all athletes to be satisfied with a single training program due to the fact that they have different physiological characteristics and needs. However, paucity studies have been introduced a specific training program for high school sprinters. Therefore, this study was designed to help develop and introduce the training program with a physical examination to enhance sprinting performance for experienced high school sprinters. VO2max, muscular strength, basic physical ability, and body composition were measured before and after a 24 week training program. The following are the conclusions based on the results of this study: 1) body fat percentage was increased after 24 weeks of training. Fat free mass and the amount of water in the body increased by 1.5% and 1.1% respectively, 2) $VO_2$maxand anaerobic threshold level showed a significant increase after 24 weeks of training, 3) exercise duration and anaerobic threshold duration were also increased after 24 weeks of training, but not statistically significant, and 4) muscular strength significantly increased due to the execution of combined weight training and circuit training. Development and implementation of the training program in this study made sprinters' physical capacities better in VO2max, anaerobic threshold, and muscular strength and body composition. Also, sprinters were able to increase fat free mass through 24 weeks of training due to increased muscle mass. Therefore, a training program for high school sprinters should include a physical examination to enhance sprinting performance and prevent sports injuries.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.625-637
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• 2009

With advent of TV environment and increasing of variety of program contents, users are able to experience more various and complex environment for watching TV contents. According to the change of content watching environment, users have to make more efforts to choose his/her interested TV program contents or TV channels than before. Also, the users usually watch the TV program contents with their own regular way. So, in this paper, we suggests personalized TV program schedule recommendation system based on the analyzing users' TV watching history data. And we extract the users' watched program patterns using the sequential pattern mining method. Also, we proposed a new sequential pattern mining which is suitable for TV watching environment and verify our proposed method have better performance than existing sequential pattern mining method in our application area. In the future, we will consider a VoD characteristic for extending to IPTV program schedule recommendation system.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.10
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• pp.87-96
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• 2004

These days, it is essential that a business-class hotel provide customers with Internet service. So the most hotels have been installing facilities actively for Internet service. Businessmen also want to use Internet service level to their own office or home in hotel room. But now TV and VoD(partial) based-on CATV in hotel is supplied, and the additional network are installed for Internet service. The existing TV also must be replaced to HDTV within 2 or 3 years. The objective of this paper is to implement the next generation hotel multimedia service system using xDSL technology, VLAN mapping technology, and QoS technology. This system can provide each room in hotel with high-quality video service and Internet service simultaneously, and can also supply Internet access service using wireless LAN for the Places, such as lobby, conference room, and coffee shop in hotel. Therefore, this system can create the new market in hotel multimedia service field by connecting xDSL technology to VLAN mapping technology for charging and QoS technology for video stream transmission.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.275-280
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• 2009

The direct incorporation of vanadium into the three-dimensional(3-D) cubic Ia3d mesostructure designated as V-KIT-6 was carried out hydrothermally using a Pluronic P123 and n-butanol as the structure-directing mixture, tetraethylorthosilicate(TEOS) as the silica source and $NH_4VO_3$ as the vanadium source. The obtained V-KIT-6 showed a very high specific surface area ${\sim}1,000m^2/g$ with tunable pore diameters in narrow distribution of sizes ~6.0 nm. The coordination and nature of V sites in V-KIT-6 are characterized by $^{51}V$-spin-echo NMR analysis. The calcined V-KIT-6 materials showed excellent catalytic activity in the direct oxidation of styrene using tert-butyl hydroperoxide(TBHP) as an oxidant.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2006.11a
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• pp.239-244
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• 2006

최근 인터넷에서 많은 관심을 보이고 있는 개인 미디어(UCC;User Created, Contents, VC2;Viewer Created Contents, 이하 UCC-사용자가 직접 제작한 미디어 콘텐츠를 불특정 다수에게 제공하는 서비스) 중에 비디오/오디오 콘텐츠를 영상 콘텐츠의 기본적인 매체라 할 수 있는 TV상에서 직접 즐길 수 있다면 미디어의 대상과 그 미디어의 Entertainment적인 효과는 배가될 것이다. 디지털 케이블 방송에서 UCC와 같은 다양하고 많은 미디어 콘텐츠를 디지털 TV상에서 서비스를 하고자 한다면 현재의 OCAP(OpenCable Application Plat form)기반에서는 RVOD(Real Video on Demand)와 동일한 서비스 모델을 가져야 하는 부담과 UCC 제공을 위한 방송 플랫폼별 인터페이스가 필요할 것이다. 이러한 문제점을 Return Path를 통한 RTP(Real-time Transport Protocol;RFC1889)을 이용해서 기존의 VoD(Video on Demand)스트림의 대역에서 분리하고 별도의 VOD프로토콜을 구현함으로써 라이브 방송환경과 동일한 인프라의 지속적인 확장보다는 일반적인 네트워크 프로토콜을 이용하여 VoD서비스를 위한 인프라에 많은 영향을 받지 않는 서비스가 가능할 수 있을 것이다. 따라서 본 논문에서는 RTP를 위한 Set-Top-Box상의 다운로드 가능한 구조의 클래스 분석과 클라이언트 대응의 UCC Transcoding 및 전송을 위한 스트리밍 서버의 설계에 중점을 두고 경량화 된 VOD서비스 및 시스템을 설계함으로써 방송환경 하에 On-Demand서비스의 효율적인 확장성과 보다 많은 콘텐츠 등록 및 활용의 기회를 가져올 수 있을 것으로 기대한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.11C
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• pp.51-63
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• 2001

According to the popular use of the multimedia services in distributed environments, the need for the variable multimedia communication technologies have been presented today. In order to support the efficient transmission multimedia streams, the multicasting, and the interoperability between multimedia applications in distributed environments, the development of the open exclusive multimedia communication systems and the provision of the control and management methodologies for media streams have been required. In order support the realtime transmission of multimedia stream in distributed environments. the protocols such as RTP, RSVP, and RTSP have been standardized. For supporting the interoperability between multimedia applications and the control and management of streams, the distributed processing platforms such as CORBA by OMG and DSM-CC by DAVIC were published. In this paper, we introduce the CORBA-based distributed multimedia communication system which support the realtime transmission, control, and management of multimedia streams and provide the interoperability between multimedia applications. Finally, we present the QoS measurement results by the interoperability between our systems and VoD systems.